Revert "Enable socket reuse based on framework"

Author: honfika

src/Titanium.Web.Proxy/Helpers/RunTime.cs

@@ -1,8 +1,6 @@
-using System;
-using System.Reflection;
+using System;
 using System.Text;
 using System.Runtime.InteropServices;
-using System.Runtime.Versioning;
 
 namespace Titanium.Web.Proxy.Helpers
 {
@@ -43,63 +41,7 @@ public static class RunTime
         public static bool IsUwpOnWindows => IsWindows && UwpHelper.IsRunningAsUwp();
 
         public static bool IsMac => isRunningOnMac;
-        
-        /// <summary>
-        /// Is socket reuse available to use?
-        /// </summary>
-        public static bool IsSocketReuseAvailable => isSocketReuseAvailable();
-
-        private static bool? _isSocketReuseAvailable;
-
-        private static bool isSocketReuseAvailable()
-        {
-            // use the cached value if we have one
-            if (_isSocketReuseAvailable != null)
-                return _isSocketReuseAvailable.Value;
-
-            try
-            {
-                if (IsWindows)
-                {
-                    // since we are on windows just return true
-                    // store the result in our static object so we don't have to be bothered going through all this more than once
-                    _isSocketReuseAvailable = true;
-                    return true;
-                }
-
-                // get the currently running framework name and version (EX: .NETFramework,Version=v4.5.1) (Ex: .NETCoreApp,Version=v2.0)
-                string ver = Assembly.GetEntryAssembly()?.GetCustomAttribute<TargetFrameworkAttribute>()?.FrameworkName;
 
-                if (ver == null)
-                    return false; // play it safe if we can not figure out what the framework is
-
-                // make sure we are on .NETCoreApp
-                ver = ver.ToLower(); // make everything lowercase to simplify comparison
-                if (ver.Contains(".netcoreapp"))
-                {
-                    var versionString = ver.Replace(".netcoreapp,version=v", "");
-                    var versionArr = versionString.Split('.');
-                    var majorVersion = Convert.ToInt32(versionArr[0]);
-
-                    var result = majorVersion >= 3; // version 3 and up supports socket reuse
-
-                    // store the result in our static object so we don't have to be bothered going through all this more than once
-                    _isSocketReuseAvailable = result;
-                    return result;
-                }
-
-                // store the result in our static object so we don't have to be bothered going through all this more than once
-                _isSocketReuseAvailable = false;
-                return false;
-            }
-            catch
-            {
-                // store the result in our static object so we don't have to be bothered going through all this more than once
-                _isSocketReuseAvailable = false;
-                return false;
-            }
-        }
-        
         // https://github.com/qmatteoq/DesktopBridgeHelpers/blob/master/DesktopBridge.Helpers/Helpers.cs
         private class UwpHelper
         {

src/Titanium.Web.Proxy/Network/Tcp/TcpConnectionFactory.cs

@@ -315,7 +315,8 @@ private async Task<TcpServerConnection> createServerConnection(string remoteHost
                         tcpClient.SendTimeout = proxyServer.ConnectionTimeOutSeconds * 1000;
                         tcpClient.LingerState = new LingerOption(true, proxyServer.TcpTimeWaitSeconds);
 
-                        if (proxyServer.ReuseSocket && RunTime.IsSocketReuseAvailable)
+                        // linux has a bug with socket reuse in .net core.
+                        if (proxyServer.ReuseSocket && RunTime.IsWindows)
                         {
                             tcpClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
                         }

src/Titanium.Web.Proxy/ProxyServer.cs

@@ -654,7 +654,8 @@ private void listen(ProxyEndPoint endPoint)
         {
             endPoint.Listener = new TcpListener(endPoint.IpAddress, endPoint.Port);
 
-            if (ReuseSocket && RunTime.IsSocketReuseAvailable)
+            // linux/macOS has a bug with socket reuse in .net core.
+            if (ReuseSocket && RunTime.IsWindows)
             {
                 endPoint.Listener.Server.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
             }